Purification and properties of the major pectinesterases in lemon fruits (<i>Citrus limon</i>)

Macdonald, Helen; Evans, Roger; Spencer, Wendy J

doi:10.1002/jsfa.2740620209

Cited by 50 publications

(45 citation statements)

References 9 publications

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“…2) indicating that PME from guava fruit carried either a net positive charge or did not carry any charge under the experimental conditions. In this respect, the guava PME seems to resemble that of banana (Brady 1976), flax cell wall (Gafe et al 1992) and lemon (MacDonald et al 1993). Fractions were pooled on the basis of specific activity, concentrated against solid sucrose and applied to a column of sephadex G-100.…”

Section: Resultsmentioning

confidence: 91%

Partial purification and characterization of pectinmethylesterase from ripening guava (Psidium guajava L.) fruits

et al. 2008

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Employing the techniques of (NH 4 ) 2 SO 4 fractionation, ion exchange chromatography on DEAE cellulose and gel filtration through Sephadex G-100, pectinmethylesterase (EC 3.1.1.11) was purified from guava (Psidium guajava L.) fruits var. Hisar Safeda harvested at turning stage of maturity to 129-fold with 28% recovery. Molecular weight as determined by gel filtration was found to be 51 kDa and the enzyme preparation exhibited the same molecular weight under native (Native-PAGE) and denaturating conditions (SDS-PAGE) indicating that the enzyme was a monomer. With pectin as the substrate, it exhibited the Michaelis Menten kinetics with K m value of 3.1 g l -1 . The enzyme was found to be stimulated by Ca ?? and Na ? and inhibited competitively by Dgalacturonic acid with K i value of 1.97 mM. The enzyme was completely inactivated by iodine while with diethyl pyrocarbonate and N-acetylimidazole, the enzyme was inhibited up to the extent of 56 and 45%, respectively. However, DTNB had no inhibitory effect whatsoever precluding the participation of any -SH group in the active centre. It is tentatively proposed that the enzyme has tyrosine and histidine residues at its active centre.

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Section: Resultsmentioning

confidence: 91%

Partial purification and characterization of pectinmethylesterase from ripening guava (Psidium guajava L.) fruits

et al. 2008

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“…The elution results of PME1 and PME2 activity resulted in purification factors of 389 and 125 (the steps are summarized in Table 1 and in Figs 1-3). The occurrence of multiple forms of PME from acerola was expected because isoforms of PME from fruits have been described by Versteeg et al, 28 Seymour et al, 15 Macdonald et al 34 column. ž , PME specific activity; , protein content.…”

Section: Resultsmentioning

confidence: 92%

Purification and characterization of pectin methylesterase from acerola (Malpighia glabra L.)

2007

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The enzyme pectinmethylesterase (PME) from acerola was extracted and purified by gel anion-exchange chromatography (Q Sepharose) and filtration on Sephadex G-100. The results showed two different PME isoforms (PME1 and PME2), with molecular masses of 25.10 and 5.20 kDa, respectively. PME1 specific activity increased by 9.63% after 60 min incubation at 98 • C, while PME2 retained 66% of its specific activity under the same conditions. The K m values of PME1, PME2 and concentrated PME were 0.94, 0.08 and 0.08 mg mL −1 , respectively. The V max value of PME1, PME2 and concentrated were 204.08, 2, 158.73 and 2.92 µmol min −1 mg −1 protein, respectively.

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“…The mechanism of de-esterification by PE may also influence cation binding and PE activation. Macdonald et al (1993) pu-rified and characterized PE from lemon endocarp and peel. Deesterification of commercial pectin by lemon endocarp PE resulted in a clear gel, whereas the lemon peel PE resulted in a flocculated precipitate.…”

Section: Discussionmentioning

confidence: 99%

Inorganic Cations and Polyamines Moderate Pectinesterase Activity

Leiting

Wicker

1997

Journal of Food Science

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Inorganic and organic cations influenced pectinesterase (PE) activity and solubilization from Marsh grapefruit pulp. Activity increased to 281%, 183%, and 130% with lead acetate (6.8 mM), ferric chloride (0.2 mM), and calcium chloride (20 mM), respectively. The polyamines, putrescine, spermidine, and spermine had negligible stimulating effect. All cations tested inhibited PE activity at higher concentrations. Solubilization of total PE was decreased and thermostable PE (TS-PE) was not affected by polyamines. There was a progressive decline in total PE activity above 1.6 mM spermidine, 7.6 mM putrescine and 20.0 mM spermine. Loss of activity upon solubilization suggests that the TL-PE-pectate complex stabilized TL-PE. No change in TS-PE activity suggests that it may be bound with greater affinity, physically entrapped, or non-electrostatically bound.

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Purification and properties of the major pectinesterases in lemon fruits (Citrus limon)

Cited by 50 publications

References 9 publications

Partial purification and characterization of pectinmethylesterase from ripening guava (Psidium guajava L.) fruits

Partial purification and characterization of pectinmethylesterase from ripening guava (Psidium guajava L.) fruits

Purification and characterization of pectin methylesterase from acerola (Malpighia glabra L.)

Inorganic Cations and Polyamines Moderate Pectinesterase Activity

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